This invention relates to an electrical junction box to be mounted on a motor vehicle, and more particularly relates to an electrical junction box provided with connecting bolts to which electrical power supply terminals are coupled.
Heretofore, an electrical junction box such as a fuse box, to which electrical power supply terminals from a battery are connected, is installed in an engine room in a motor vehicle to obtain good maintenance of electrical power supply paths in the motor vehicle and to efficiently branch an electrical power source.
When a battery becomes a superdischarged condition in a motor vehicle, the electrical junction box provided with a relief hardware structure has been proposed so that the battery under the superdischarged condition receives electrical power supply from a battery in another motor vehicle or an emergency potable electrical power source (hereinafter referred to “a jump starter”) to start an engine. Such a relief terminal hardware structure has been disclosed in, for example, JP 2004-134278 A and JP 2008-123928 A. In particular, in a current hybrid type motor vehicle or the like, since it is difficult to install an upsized battery in an engine room, the battery can be disposed in a trunk room or the like different from the engine room. In this case, if an electrical junction box provided with the relief terminal hardware structure is installed in the engine room, it will be possible to deal with the discharged battery merely by opening a hood of the engine room. Accordingly, such electrical junction box has been available.
However, in the above electrical junction box, a relief terminal must be specially made of a bus bar, and in addition, a distinguishable cover member that protects the relief terminal must be provided in the electrical junction box in order to prevent an error in coupling. Accordingly, this will increase the number of parts and will involve complicated steps in production.
It may be considered that an external electrical power supply cable is connected to a connecting bolt, to which a feeder from a battery is connected, to receive an electrical power supply from the jump starter in the electrical junction box. However, the electrical junction box such as a fuse box that receives the electrical power supply from the battery is provided with a plurality of connecting bolts such as a starter connecting bolt to which a feeder to a starter is connected, and an alternator connecting bolt to which a feeder from an alternator is connected, as well as a battery connecting bolt to which a feeder from a battery is connected. Accordingly, there is a possibility that an external electrical power supply cable from the jump starter may be connected to another connecting bolt by mistake. Particularly, if the external electrical power supply cable from the jump starter is connected to the alternator bolt connected to a feeder from the alternator, a load is applied to the alternator and its function will be lowered.
The exemplary embodiments of the invention address the above problems and other problems by, for example, providing a new electrical junction box in which even if a plurality of bolts are connected to external electrical cables, an external electrical power supply cable from a jump starter can be surely connected to a target connecting bolt, thereby avoiding a problem of an error in coupling by a simple structure.
In an exemplary embodiment an electrical junction box includes: a battery connecting bolt to which a feeder from a battery is connected, and an alternator connecting bolt to which a feeder to an alternator is connected. A coupling error check wall is provided around the alternator connecting bolt to restrain a space around the alternator connecting bolt. A feeder terminal to an alternator and a fixing nut are permitted to be mounted on the alternator connecting bolt and an alligator clip for jump starter is prevented to be connected to the alternator connecting bolt. A space around the battery connecting bolt is set to be larger than the space around the alternator connecting bolt to permit the alligator clip for jump starter to be connected to the battery connecting bolt.
When the battery reaches a superdischarged condition, an external electrical power supply cable (an alligator clip for jump starter) is connected to the battery connecting bolt to which a battery terminal is attached so as to supply an electrical power to the superdischarged battery in the electrical junction box installed in the engine room. Accordingly, it is possible to supply an external electrical power to the superdischarged battery merely by connecting the alligator clip for jump starter to the conventional battery connecting bolt without providing any special relief terminal for the superdischarged battery.
In addition, since the coupling error check wall is provided on the space around the alternator connecting bolt, it is possible to prevent the alligator clip for jump starter from being connected to the alternator connecting bolt by mistake and to avoid a lower performance of the alternator based on excessive load to the alternator upon an error in coupling. It is preferable that the coupling error check wall is provided on each of opposite sides of the alternator connecting bolt. It is more preferable that the coupling error check wall is provided to surround three sides of the alternator connecting bolt.
Particularly, because the coupling error check wall is provided on the space around the alternator connecting bolt so that the feeder is permitted to be connected to the alternator connection bolt and the alligator clip for jump starter is prevented from being connected to the alternator connecting bolt, it is possible to easily connect the feeder terminal to the alternator and to completely prevent the alligator clip for jump starter from being connected to the alternator connecting bolt.
In an exemplary embodiment, the coupling error check wall protrudes over an end of the alternator connecting Thus, it is possible to prevent the protruding end of a shaft portion of the alternator connecting bolt from protruding outward (upward) from a protruding end of the coupling error check wall.
Because the coupling error check wall is provided around the alternator connecting bolt, it is possible to positively connect the external electrical power supply cable from the jump starter to the target battery connecting bolt, thereby avoiding the error in coupling.